My understanding is bounties are used to attract more viewers for a possible difficult or an urgent question.
My question is: what if I already see somebody is answering my question and putting extra ...

I am really confused about this. My question didn't get much attention even after offering the bounty.
What will happen to my bounty now? Will I be getting it back or is there any way to increase its ...

For questions, you can attract attention by offering a bounty.
Now let's say you worked hard and offered what you feel is a very good answer (possibly a lot better than the currently accepted answer) ...

I've provided an answer on a question with a bounty, however once my answer was accepted I was not credited the bounty. The question in question is:
Ruby/Rails: accessing a variable inside a .each on ...